The can opener has evolved from a rudimentary bayonet-sickle hybrid to today’s more modern design, which typically has a propeller-like knob called a driving handle that users turn to move a small, circular blade around the top of a can. Traditional can openers puncture the top and remove the metal lid inside the can’s rim. Safety can openers cut into the side of the can at the top and allow users to remove both the metal lid and the rim itself; this creates a smoother, and therefore safer, edge.
In our most recent testing, we chose a safety opener as our winner for two reasons: its sleek, comfortable design and easy lid removal. However, we stock the test kitchen with our winning equipment so we can use it regularly and monitor its performance over time, and after a while, we started hearing some complaints about our winning can opener. Our test cooks said that this opener was confusing because they couldn’t always tell when the opener had successfully attached to the can. Unlike a traditional can opener that clamps down tightly as it punctures the lid, this model latches on to the side and doesn’t give a clear audible or tactile indication that it’s properly attached.
Taking these comments into account, we decided to retest. We chose seven popular models—four traditional openers and three safety openers—priced from about $8 to about $55. We opened cans of varying sizes—from hefty cans of whole tomatoes to petite cans of tomato paste—and found that we definitely preferred one style of opener to the other.
Two of the safety can openers were especially confusing to use because their blades attached to the tops of cans instead of the sides. This meant that their blades sat on the bottom of the opener, blocking our view and making it hard to correctly position them on cans. Once we did it a few times, the process became easier, but it still caused confusion among testers; their comments included “I’m not actually sure how to put this one on,” “Is that right?” and “You might have to give me some guidance here.” A third safety opener—the winner from our previous testing—latched on to the side of a can, so its cutting mechanism was visible and it was slightly easier to position correctly but still not as intuitive as a traditional model.
In light of the feedback we got from test cooks, we decided to place more emphasis on an opener’s ease of use rather than its performance. The traditional models were much easier to attach to cans than the safety openers were, and we got clear confirmation that they were latched: We could see the blade puncture the lid and hear the hiss of air escaping from the can. There was no confusion.
The driving handle is arguably the most important element of a can opener: It’s the part that users have to turn to open the can. As such, it needs to be both comfortable to grip and easy to turn.
The driving handles of the models in our lineup were made of metal or plastic and were either straight or slightly curved, though one model featured a bulbous, semicircular knob. They were all comfortable to hold regardless of material or shape, but there were clear differences in how comfortable they were to turn.
The driving handles of two of the safety openers were especially challenging. “That was really hard!” said one tester of one model’s handle. Another opener’s handle was deemed “very tight, very hard to turn.” We asked our science research editor what might make safety openers’ driving handles harder to turn. He explained that the side of the can is typically a heavier gauge of metal than the can’s top and therefore would require more force to cut through.
The driving handles on each of the traditional openers were easy to turn. Our favorite model had a driving handle that was “a little more smooth and comfortable.” At 3½ inches from end to end, its driving handle was the longest in the lineup. This is significant because a driving handle acts as a lever rotating around a fulcrum, and a longer lever imparts greater mechanical advantage. It takes less force to rotate a longer driving handle than a shorter one, which helps explain why our winner was so easy to use.
Two of the safety openers required us to turn the driving handle backward to release the opener from the can, a trick that wasn’t obvious to a lot of our testers.
Traditional openers were more intuitive to use: Just pull the handles apart and off comes the opener. However, one traditional opener was more of a nuisance—it had a button that we had to press to attach it and to remove it from the can, which felt like an unnecessary and cumbersome step. Our favorite opener effortlessly detached from cans.
We really liked that the safety openers removed lids cleanly without letting them sink down into the can. However, there were some minor issues with this approach. A couple of openers featured built-in pliers resembling tiny bird beaks to help pull off lids, but they weren’t very useful. As one tester explained, “I don’t think I would use these pliers because that was probably harder than just pulling it off myself.”
Another issue: With all three safety openers we noticed stringy yellow strands stretching from the can to the lid as we pulled the lid off. “It’s weird to see the glue,” said one tester, and we agreed. None of this glue got into the food (as far as we could tell), but we’d rather not risk it.
Traditional openers had their own issues as well—the biggest being sinking lids. When draining canned tuna, a sinking lid is a definite asset, but in all other cases, we had to dip our fingers into food to fish them out. One model had a magnet designed to grab lids before they sank, but paradoxically, we ended up pushing the lid farther down trying to get the magnet to attract the lid. Overall, there was no perfect lid-removal process for any of the openers in our lineup.
In general, most models looked like new even after opening lots of cans and being repeatedly cleaned. But after washing one safety model, water remained trapped in its plastic body. It leaked water as we used it and expelled more when we shook it, but there was no way to ensure that all the water was out. We worried about the risk of mold.
The handles of all the traditional models were covered with rubber, and one model’s handle cover came loose during testing. The manufacturer said it doesn’t use an adhesive to keep the rubber in place, but that “the handle covers are formed to fit snugly on the can opener handles and should require an excessive amount of force to remove.” (We didn’t apply excessive force during testing.) We checked the other two traditional models and found we could remove the handles if we pulled hard enough, but they didn’t slide off on their own.
In the end, our winner was the EZ-DUZ-IT Can Opener, a traditional can opener. It was easy to use, and its driving handle, the longest of all the models we tested, made it especially comfortable to operate.